from threading import Thread
import time

# 线程与全局变量的关系
g_num = 100


def work1():
    global g_num
    for i in range(3):
        g_num += 1

    print("=== in work1, g_num is %d ===" % g_num)


def work2():
    global g_num
    print("=== in work2, g_num is %d ===" % g_num)


print("=== 线程创建前 g_num is %d ===" % g_num)

t1 = Thread(target=work1)

t1.start()
# 延迟一会，保证t1线程完成
time.sleep(1)
t2 = Thread(target=work2)

t2.start()

'''
=== 线程创建前 g_num is 100 ===
=== in work1, g_num is 103 ===
=== in work2, g_num is 103 ===
'''